Export a different environment filename per iteration

I’m using newman and want to do the following: I want Newman to export the environment filename with a timestamp for each iteration. Does anyone know how to do this? Here is my command which I thought would work. I’m on a mac running this command on my machine . Newman is only creating 1 filename with the timestamp. It’s not creating it for each run.

newman run filename.postman_collection.json -e QA3.postman_environment.json --export-environment QA3_$(date +%Y%m%d_%H%M).postman_environment.json -n 2

Thanks for your help
Traci